The present inventions relate to water recirculation systems in laundry washers, and particularly those suitable for use in a front load (e.g., horizontal axis) washer. Such systems may use a single outlet located on the upper side of the tub bellows for both inputting fresh water and inputting water recirculated from the bottom (sump) of the tub, or alternatively separate respective outlets may be used for these two circuits. Such a recirculation system takes wash water from the bottom of the tub and pumps it to an upper part of the rotatable drum to help wet the clothes and improve wash and rinse action.
Some models of front load washing machines in the marketplace have a recirculation pump and system that allows the water inside the wash tub to be recirculated from bottom to top. With such a system, there is a constraint in that the system should not cause a situation where the soap inside the machine suds to such a degree that the suds cannot be effectively removed from the clothes during the rinse cycle(s). On the other hand, it is desirable to get the clothes wet with detergent as early in the wash cycle as possible to maximize the wash performance of the machine. These two constraints are somewhat contradictory. The first makes it desirable to have the recirculation pump used on a limited basis. The second dictates that the recirculation pump be used as much as possible.
It is also typical in front load washing machines to have a wash phase and then an intermediate spin followed by a first rinse phase and another intermediate spin, followed by a final rinse phase. Additives such as bleach and fabric softener may or not be added during the rinses. The main function of the rinses is to remove detergent from the clothes after the wash portion of the cycle. Recirculation could be beneficial in each of these phases if it could be implemented in a manner that effectively controls excess sudsing.
In order to meet the contradictory requirements of avoiding excess suds formation, and on the other hand maximize the beneficial use of water recirculation, there is a need to increase the efficiency with which the recirculation system is used. In addition, it is desirable to reduce the amount of water consumption in the wash process without sacrificing wash performance.